coredump: Improve man pages
This commit is contained in:
Peter Mattern
Zbigniew Jędrzejewski-Szmek
parent
77ff6022fa
commit
246ba4aaa9
|
|
@ -45,7 +45,7 @@
|
|||
|
||||
<refnamediv>
|
||||
<refname>coredumpctl</refname>
|
||||
<refpurpose>Retrieve coredumps from the journal</refpurpose>
|
||||
<refpurpose>Retrieve and process saved core dumps and metadata</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<refsynopsisdiv>
|
||||
|
|
@ -60,9 +60,10 @@
|
|||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para><command>coredumpctl</command> may be used to
|
||||
retrieve coredumps from
|
||||
<citerefentry><refentrytitle>systemd-journald</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
|
||||
<para><command>coredumpctl</command> is a tool that can be used to retrieve and process core
|
||||
dumps and metadata which were saved by
|
||||
<citerefentry><refentrytitle>systemd-coredump</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -71,18 +72,23 @@
|
|||
<para>The following options are understood:</para>
|
||||
|
||||
<variablelist>
|
||||
|
||||
<xi:include href="standard-options.xml" xpointer="help" />
|
||||
<xi:include href="standard-options.xml" xpointer="version" />
|
||||
|
||||
<varlistentry>
|
||||
<term><option>--no-legend</option></term>
|
||||
|
||||
<listitem><para>Do not print column headers.
|
||||
</para></listitem>
|
||||
<listitem><para>Do not print column headers.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<xi:include href="standard-options.xml" xpointer="no-pager" />
|
||||
|
||||
<varlistentry>
|
||||
<term><option>-1</option></term>
|
||||
|
||||
<listitem><para>Show information of a single coredump only,
|
||||
instead of listing all known coredumps. </para></listitem>
|
||||
<listitem><para>Show information of a single core dump only, instead of listing
|
||||
all known core dumps.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
|
|
@ -110,11 +116,11 @@
|
|||
</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<xi:include href="standard-options.xml" xpointer="help" />
|
||||
<xi:include href="standard-options.xml" xpointer="version" />
|
||||
<xi:include href="standard-options.xml" xpointer="no-pager" />
|
||||
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Commands</title>
|
||||
|
||||
<para>The following commands are understood:</para>
|
||||
|
||||
|
|
@ -124,7 +130,15 @@
|
|||
|
||||
<listitem><para>List core dumps captured in the journal
|
||||
matching specified characteristics. If no command is
|
||||
specified, this is the implied default.</para></listitem>
|
||||
specified, this is the implied default.</para>
|
||||
|
||||
<para>It's worth noting that different restrictions apply to
|
||||
data saved in the journal and core dump files saved in
|
||||
<filename>/var/lib/systemd/coredump</filename>, see overview in
|
||||
<citerefentry><refentrytitle>systemd-coredump</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
|
||||
Thus it may very well happen that a particular core dump is still listed
|
||||
in the journal while its corresponding core dump file has already been
|
||||
removed.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
|
|
|
|||
|
|
@ -47,7 +47,7 @@
|
|||
<refname>systemd-coredump</refname>
|
||||
<refname>systemd-coredump.socket</refname>
|
||||
<refname>systemd-coredump@.service</refname>
|
||||
<refpurpose>Log and store core dumps</refpurpose>
|
||||
<refpurpose>Acquire, save and process core dumps</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<refsynopsisdiv>
|
||||
|
|
@ -58,36 +58,17 @@
|
|||
|
||||
<refsect1>
|
||||
<title>Description</title>
|
||||
<para><command>systemd-coredump</command> is a system service that can acquire core dumps
|
||||
from the kernel and handle them in various ways.</para>
|
||||
|
||||
<para><command>systemd-coredump</command> can be used as a helper
|
||||
binary by the kernel when a user space program receives a fatal
|
||||
signal and dumps core. For it to be used in this capacity, it must
|
||||
be specified by the
|
||||
<varname>kernel.core_pattern</varname> <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
setting. The syntax of this setting is explained in
|
||||
<citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||||
Systemd installs <filename>/usr/lib/sysctl.d/50-coredump.conf</filename> which configures
|
||||
<varname>kernel.core_pattern</varname> to invoke <command>systemd-coredump</command>.
|
||||
This file may be masked or overridden to use a different setting following normal
|
||||
<citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||||
rules.</para>
|
||||
|
||||
<para>The behavior of a specific program upon reception of a
|
||||
signal is governed by a few factors which are described in detail
|
||||
in <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||||
In particular, the coredump will only be processed when the
|
||||
related resource limits are high enough. For programs started by
|
||||
<command>systemd</command>, those may be set using
|
||||
<varname>LimitCore=</varname> (see
|
||||
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
|
||||
<para>Core dumps can be written to the journal or saved as a file. Once saved they can be retrieved
|
||||
for further processing, for example in
|
||||
<citerefentry project='man-pages'><refentrytitle>gdb</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
|
||||
</para>
|
||||
|
||||
<para>The behaviour of <command>systemd-coredump</command> is configured through
|
||||
<filename>/etc/systemd/coredump.conf</filename> and other configuration files. See
|
||||
<citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||||
for details. By default, <command>systemd-coredump</command> will log the coredump including a
|
||||
backtrace if possible, and store the core (contents of process' memory contents) in an external
|
||||
file on disk in <filename>/var/lib/systemd/coredump</filename>.</para>
|
||||
<para>By default, <command>systemd-coredump</command> will log the core dump including a backtrace
|
||||
if possible to the journal and store the core dump itself in an external file in
|
||||
<filename>/var/lib/systemd/coredump</filename>.</para>
|
||||
|
||||
<para>When the kernel invokes <command>systemd-coredump</command> to handle a core dump,
|
||||
it will connect to the socket created by the <filename>systemd-coredump.socket</filename>
|
||||
|
|
@ -96,21 +77,57 @@
|
|||
and <filename>systemd-coredump@.service</filename> are helper units which do the actual
|
||||
processing of core dumps and are subject to normal service management.</para>
|
||||
|
||||
<para>The log entry and a backtrace are stored in the journal, and can be viewed with
|
||||
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
|
||||
<citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
may be used to list and extract coredumps or load them in
|
||||
<citerefentry project='man-pages'><refentrytitle>gdb</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
|
||||
<para>The behavior of a specific program upon reception of a signal is governed by a few
|
||||
factors which are described in detail in
|
||||
<citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||||
In particular, the core dump will only be processed when the related resource limits are sufficient.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Configuration</title>
|
||||
<para>For programs started by <command>systemd</command> process resource limits can be set by directive
|
||||
<varname>LimitCore=</varname>, see
|
||||
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||||
</para>
|
||||
|
||||
<para>The coredump helper is invoked anew each time. Therefore, any configuration
|
||||
changes will take effect on the invocation of <command>systemd-coredump</command>.
|
||||
<para>In order to be used <command>systemd-coredump</command> must be configured in
|
||||
<citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
parameter <varname>kernel.core_pattern</varname>. The syntax of this parameter is explained in
|
||||
<citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||||
Systemd installs the file <filename>/usr/lib/sysctl.d/50-coredump.conf</filename> which configures
|
||||
<varname>kernel.core_pattern</varname> accordingly. This file may be masked or overridden to use a different
|
||||
setting following normal
|
||||
<citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||||
rules.
|
||||
If the sysctl configuration is modified, it must be updated in the kernel before
|
||||
it takes effect, see
|
||||
<citerefentry><refentrytitle>systemd-sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
<citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
and
|
||||
<citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
|
||||
<citerefentry><refentrytitle>systemd-sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
|
||||
</para>
|
||||
|
||||
<para>The behaviour of <command>systemd-coredump</command> itself is configured through the configuration file
|
||||
<filename>/etc/systemd/coredump.conf</filename> and corresponding snippets
|
||||
<filename>/etc/systemd/coredump.conf.d/*.conf</filename>, see
|
||||
<citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. A new
|
||||
instance of <command>systemd-coredump</command> is invoked upon receiving every core dump. Therefore, changes
|
||||
in these files will take effect the next time a core dump is received.</para>
|
||||
|
||||
<para>Resources used by core dump files are restricted in two ways. Parameters like maximum size of acquired
|
||||
core dumps and files can be set in files <filename>/etc/systemd/coredump.conf</filename> and snippets mentioned
|
||||
above. In addition the storage time of core dump files is restricted by <command>systemd-tmpfiles</command>,
|
||||
corresponding settings are by default in <filename>/usr/lib/tmpfiles.d/systemd.conf</filename>.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Usage</title>
|
||||
<para>Data stored in the journal can be viewed with
|
||||
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
as usual.
|
||||
<citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
can be used to retrieve saved core dumps independent of their location, to display information and to process
|
||||
them e.g. by passing to the GNU debugger (gdb).</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -119,6 +136,7 @@
|
|||
<citerefentry><refentrytitle>coredump.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||||
<citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-sysctl.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
|
||||
|
|
|
|||
Loading…
Reference in a new issue